Tissue-simulating phantoms are artificial models with physical properties (e.g., absorption and scattering) similar to biological tissue. They are widely used for performance testing of clinical medical imaging systems (e.g., ultrasound, computed tomography (CT), and magnetic resonance imaging (MRI)). In the field of biophotonics, tissue-simulating phantoms are also used for testing non-imaging diagnostic devices based on spectroscopy and other approaches. The optimal design of a biophotonic phantom depends on the modality and application, and when a higher degree of realism is desired, designs can be customized to individual biological tissue types. The development of phantoms made of specialized materials to mimic biologically-realistic properties has enhanced the quality of these device evaluation tools.
Two relevant characteristics of biophotonic phantoms are the biological relevance of the phantom's optical properties and its long-term stability. Some stable biophotonic phantoms are fabricated from solid polymers and contain artificial dyes that simulate the optical absorption properties of tissue. However, such phantoms do not provide a realistic spectral representation of a ubiquitous biological absorber, hemoglobin (Hb).